1. Field of the Invention
The present invention relates to a spindle control system of a numerical control apparatus, and more specifically, to a spindle control system by which spindles controlled by respective paths, or path controllers, are changed.
2. Description of the Related Art
Recent machine tools are complex machines provided with a number of independently controllable spindles, and are widely used to improve the machining efficiency and to simultaneously machine complex configurations.
In such a complex machine, an assembly of axes is controlled by a single path controller (path), which is a numerical control apparatus. Conventionally, a first path controls only a first spindle and a second path controls only a second spindle.
In conventional systems, however, since a second path cannot control a first spindle and a first path cannot control a second spindle, any improvement of the machining efficiency is limited even if a plurality of spindles are provided.